Comments on: Monday morning armchair physicist

By: Joey Johnston

Joey Johnston — Wed, 09 Dec 2009 02:29:49 +0000

yes i saw that mythbusters episode and adam even takes it to to new levels, a penny shot to the hand and to the ass. funny as hell

By: Boozer

Boozer — Sun, 17 Jun 2007 18:49:22 +0000

Here’s an idea. The terminal velocity of the bullet is much less than the muzzle velocity. So when the bullet comes back down, it’s not traveling at the muzzle velocity.

Think a little harder next time, Tom.

By: Jim

Jim — Thu, 18 Jan 2007 13:43:27 +0000

My brain now hurts! Thanks alot.

By: Lau

Lau — Sun, 03 Sep 2006 06:20:35 +0000

Your site is really good, it helped me understand this prac on terminal velocity i’m supposed to be doing in physics – I’m a yr 11 phys student – so, thanks very much!

Laurel

By: Franklin W.

Franklin W. — Fri, 18 Aug 2006 18:10:02 +0000

In response to Tom-
I’m sorry to say you are wrong, and I could go into the math, but a simple thought experiement will do- Shoot a feather or ping pong ball straight up. I can shoot it with a force (and acceleration) far greater than that of gravity, and short of destroying the object can achieve nearly any muzzle velocity I choose. On the way down however, with only the force of Earth’s gravity pulling down it against our thick atmosphere, the object will come floating back far slower than it went up. Your statement is true however on the moon.

By: Tom Green

Tom Green — Wed, 09 Aug 2006 03:47:44 +0000

Idiots, idiots, idiots. Think. A bb, a marble, no flat side, all sides equal. Read Isaac Asimov, Physics, he has the definitive answers, though with a cannonball, round object. A round bullet shot upwards experiences wind resistance and gravity holding it back. It achieves whatever altitude possible against those two factors then fall back to earth and experiences the same two factors, gravity propelling it in reverse and wind resistence equal to that which it experienced on the way up, thus when the round bullet reaches the earth it should be travelling at muzzle velocity, same at which it left earth.
Duh.

By: mike

mike — Mon, 12 Jun 2006 01:19:08 +0000

very interesting. I’ve been trying to prove my friends wrong on this all week, and got the whole “terminal velocity” thing, but they didn’t understand it. Now I have evidence to show them. Very interesting indeed

By: Ian

Ian — Fri, 19 May 2006 19:58:14 +0000

There are only 118 ridges on a dime, not 188…

By: jim

jim — Tue, 09 May 2006 21:00:17 +0000

A Canadian nickel weighs .00395kg and is slightly thinner (0.00176 versus 0.00195 m) than an American nickel. Its composition is also different. The Canadian nickel is 94.5% steel, 3.5% copper, and 2% nickel whereas its American counterpart is 75% copper and 25% nickel.

Plug the numbers into the spreadsheet and you’ll see the difference.

By: Kris

Kris — Tue, 09 May 2006 12:38:27 +0000

is there a difference in the canadian nickel and the american? if so, what difference? is the nickel content more or less? the weight must be different. what do these play on the terminal velocity